content property doesn't return the value of an attribute when attribute is dynamically inserted

This test case demonstrates the incorrect behaviour of IE8 RTW where the content property doesn't return the value of an attribute when the attribute value is dynamically inserted

Live Example

Click the 'Test' button below

Expected Results

When the 'Test' button is clicked, the title attribute value, 'Test passed!' should appear below the button.

Actual Results

In IE8 RTW, the content property doesn't return the value of the dynamically-inserted title attribute value, therefore the text 'Test passed!' isn't displayed below the button when the button is clicked.